Reduction of cutaneous atrophy

ABSTRACT

The cutaneous atrophy associated with the use of steroids topically can be ameliorated using salts of certain α-hydroxyacids.

This application is a continuation of pending application Ser. No.07/671,577 filed Mar. 19, 1991.

BACKGROUND

The use of topical steroids is known to result in certain unwanted sideeffects, among them cutaneous atrophy, or diminution of the epidermisand dermis, at or near the cite of steroid application. Such atrophy isgenerally characterized by thinning, shininess, increased transparencyand telangiectasia.

There are many regimens and a variety of reasons for treating conditionswith steroids and/or hydroxyacid-based reagents. Applicants know of noreferences to the use of hydroxyacid salts, e.g. lactates, to amelioratethe adverse effects of topical steroid usage. U.S. Pat. No. 4,105,783describes the treatment of dry skin, or "ichthyosis", using the acid,amide or ammonium salt of an α- or β-hydroxyacid. Lactic acid, orα-hydroxypropionic acid, is one of the α-hydroxyacids mentioned.

U.S. Pat. No. 4,246,261 shows topical compositions containing steroidsin which the efficacy of the steroid used is enhanced via the use ofsalts of lactic or other α-hydroxyacids, derived using various bases.

U.S. Pat. No. 4,363,815 deals with compositions for treating skininflammation or disturbed keratinization. Hydroxyacid/base reactionproducts are disclosed as useful therein.

U.S. Pat. No. 4,485,091 refers to skin creams which contain sodium andpotassium lactates as buffers.

E.P.O. Publication 0273202 discloses combinations of therapeutic agentswith hydroxycarboxylic acids or salts thereof. At page 16, an ointmentcontaining betamethasone dipropionate and 2-methyl-lactic acid isrecited.

Lac-Hydrin® lotion, a product of Westwood Squibb Pharmaceuticals, Inc.(Buffalo, N.Y.), is described on page 2285 of the 1990 Physician's DeskReference as 12% lactic acid, neutralized with ammonium hydroxide (i.e.,ammonium lactate). The lotion has a pH of 4.5-5.5 and is disclosed asuseful in treating dry, scaly skin (xerosis), ichthyosis vulgaris andthe itching associated with these conditions.

THE INVENTION

It has been discovered that certain salts of alpha-hydroxyacids thickenthe skin, specifically the viable epidermis, and increase certain dermalcomponents (ground substance) so that the atrophic effects of topicalsteroid usage are lessened.

In a preferred embodiment, a 0.05% clobetasol 17-propionate cream wasapplied to the skin of a group of subjects every morning for four weeks.Buffered ammonium lactate (12% Lac-Hydrin®) was applied eight hoursafter each steroid application. Other groups received applications ofonly steroid or ammonium lactate salt once daily.

Skin treated with only steroid showed a 51% decrease in thickness, whilethat treated with steroid followed by ammonium lactate showed only a 35%decrease in thickness.

OBJECTS OF THE INVENTION

It is one object of the invention to provide compositions and processesfor treating skin atrophy.

It is another object to provide compositions and processes forthickening skin.

It is yet another object of the invention to increase the groundsubstance in the viable epidermis of subjects and, thereby, amelioratethe effects of biological aging and/or damage by chemical agents orlight.

The compositions and the processes of the invention employ usefulquantities of salts of certain α-hydroxyacids. Optionally, they may alsoemploy one or more steroid components.

ADVANTAGES

The compositions and methods of the invention have several advantagesover other dermatological systems now in use.

One principal advantage is the lessening of the cutaneous atrophyusually associated with the topical use of steroids and some othermedicaments.

Another is the fact that, while lessening one or more of the sideeffects of such drugs as steroids, the salts of the invention do notalter the efficacy of these drugs in any way. Accordingly, there is no"masking" or "dilution" of the steroid used.

Still another advantage is the compatibility of the salts of theinvention with steroids and other topical therapeutic agents. The saltsmay be simply blended into formulations containing the steroid.

Thus, the salts of the invention may be administered either along with asteroid or other topical drug or in a separate step, that is, eitherconcomitant therewith, previous thereto or subsequent thereto. It hasbeen found that using the salt after use of the steroid can lessen theatrophic effects of the steroid without altering its beneficial effects.

The salts of the invention can also be used in any system in whichtemporary thickening of the epidermis is desired. For example, personswith known sensitivities to certain agents, e.g. sunlight or certainhair or makeup preparations, and those whose skin has becomebiologically aged can have their skin toughened or made less sensitiveby using the systems of the invention before exposing their skin toharmful agent(s).

These and other advantages of the invention will be apparent after aconsideration of the following description and claims.

DESCRIPTION OF THE DRAWINGS

A brief description of the drawings:

FIGS. 1a-1dare light micrographs of the epidermis and dermis of asubject treated as follows for four weeks.

1a. Control

1b. 12% ammonium lactate treatment

1c. clobetasol propionate treatment

1d. 12% ammonium lactate following clobetasol propionate treatment.

The amount of agent applied in each of testings 1b through 1d was 0.2ml.

The invention concerns compositions and processes for thickening skinand for lessening the atrophic effects of topical steroid usage.

Unless stated otherwise, all percentages mentioned herein are weightpercentages, based on total composition weight.

All publications referred to herein are hereby incorporated byreference.

The compositions and processes of the invention employ certain salts,optional steroids and, if desired, various additives conventionally usedin topical formulations.

SALTS

Useful salts are generally obtained via the reaction of suitable baseswith α-hydroxyacids of formula I: ##STR1## wherein R is H or a C₁₋₅hydrocarbon group.

Preferably R is an alkyl group, such as a C₁₋₃ alkyl group, with methyland ethyl groups being highly preferred. R is most preferably a methylgroup, so that salts derived from α-hydroxypropionic acid, or lacticacid, are most preferred. Mixtures of acids may be used.

The bases used to produce the salts of the invention contain eithernitrogen atoms, present as ammonium ions or amine nitrogen, or metalions.

Ammonium-containing species to be used can be, for example, NH₄ OH,HN(R¹)₃ OH, or N(R¹)₄ OH, in which each R¹ is independently a C₁₋₈ alkylor aryl group. Mixtures are operable. Ammonium hydroxide is a preferredreactant.

Amines are another group of nitrogen-containing reactants which may beused to make the salts of the invention. Useful amines include organicprimary, secondary and tertiary amines which contain 1-3 nitrogen atoms.The organic groups of these amines are generally C₁₋₈ alkyl or arylgroups, optionally substituted with one more hydroxyl groups. Preferredamines include alkanolamines, diamines, dialkylamines, dialkanolamines,alkylalkanolamines, trialkylamines, trialkanolamines, dialkyl- oralkanol-amines and alkyl diethanolamines.

Alternatively, the salts of the invention can be produced using metalion-containing reagents. Preferred metal ion-containing bases are thosewhich result in salts containing atoms of Na, K, Ca, Mg, or Li.Typically the metal ion reactants are hydroxides. Mixtures arecontemplated.

The salts of the invention are produced via conventional acid/basereactions, such as that involving ammonium hydroxide and lactic acid.Conventional reaction vessels are used. Reaction temperatures to be useddepend upon the particular reactants and the other reaction conditionsselected.

One useful source of ammonium lactate is the 12% lotion sold as"Lac-Hydrin®" by Westwood Squibb Pharmaceutical Co.

The salts of the invention will be present, when used alone informulations, in an amount ranging from about 1% to about 53%,preferably about 2% to about 38%.

It should be noted that, while the disclosure refers to salts of basesand α-hydroxyacids, it is contemplated that mere mixtures of these typesof reagents be used. Accordingly, mixtures of acids and bases, such asthose disclosed in U.S. Pat. No. 4,105,783 are also operable in theinvention.

STEROIDS

The steroids useful in the invention are any of a wide variety ofmaterials generally characterized as corticosteroids.

The steroids may be used in their base form, or they may be used as theesters, amides, ethers, etc. which are conventionally used inpharmaceutical preparations.

Steroids are generally characterized as being of high, medium, or lowpotency. Clobetasol propionate, a high potency steroid, has been foundto be very useful in the invention. However, low and moderate potencysteroids, e.g., by drocastisone and beta-methasone-17-valerate,respectively, are believed to be useful.

Among the preferred steroidal agents to be used in the invention are thecorticosteroids conventionally employed in topical dermatologicalformulations. Thus, useful agents include those listed below:

Alclometasone dipropionate

Betamethasone

Betamethasone benzoate

Betamethasone dipropionate

Betamethasone valerate

Clobetasol propionate

Clobetasol valerate

Deprodone propionate

Desflurotriamcinolone

Dexamethasone

Dexamethasone acetate

Dexamethasone sodium phosphate

Diflorasone diacetate

Flumethasone valerate

Fluocinolone acetamide

Halobetasol propionate and others in U.S. Pat. No. 4,619,921

Hydrocortisone

Hydrocortisone acetate

Hydrocortisone valerate

Mometasone furoate

Triamcinolone acetonide

Mixtures of one or more of the compounds mentioned above are operable.

In addition, the use of other conventional steroidal agents such as thefree agents and other esters and amides of the agents listed above,e.g., dexamethasone valerate, whether used alone or in mixtures, arecontemplated.

SALT/STEROID MIXTURES

While the salts of the invention can be topically applied separatelyfrom the steroid(s), they may also be mixed with them, i.e., in the sameformulation.

When salts and steroids are used in the same formulation, theconcentration of salt will be from about 1% to about 53%, preferablyabout 2% to about 38%. The concentration of steroid will be from about0.0005% to about 3.0%, preferably about 0.01% to about 1.0%.

ADDITIVES

Since the formulations of the invention are to be used topically, i.e.by application to and absorption into the skin of the subject to betreated, they will usually contain certain additional ingredients whichrender them suitable for such use. Thus, a variety of conventionalingredients, such as emulsifiers, diluents, fillers, preservatives,moisturizers, thickeners, colorants, perfumes, buffers, etc. can beemployed in these compositions in amounts of from about 0.05 to about99.5%.

The topical formulation of the invention are generally employed ascreams, lotions, ointments, gels or sprays. Other liquid or semi-solidforms are contemplated. Additives appropriate to use in these forms arealso contemplated.

Other therapeutic agents may also be used in the formulations of theinvention. Thus, antifungal agents (e.g., imidazoles), anesthetics(e.g., methyl solicylate), humectants (e.g., glycerin), antibacterials(e.g., erythromycin, clindamycin) and the like may be used. It should benoted that any additional therapeutic agents should be of such type(s)and in such amount(s) that their presence does not interfere with thefunction of the salt or the salt/steroid combination in the formulation.Generally, minor amounts of such additional therapeutic agents, i.e.,about 10% or less, preferably about 0.001% to about 5%, can be used.

pH

While the pH of the systems described herein is not critical, it isgenerally the case that compositions whose final pH values lie betweenabout 3.0 and about 7.5, and preferably about 4.0 and about 6.0, areoperable. These pH ranges assure maximum beneficial properties for thesalt in the formulations.

Depending upon the presence of a steroid or other therapeutic agent inthe formulation, the use of slightly lower pH's may be beneficial.

ADMINISTRATION

Generally, the topical formulations of the invention are administeredfrom about one to about three times, and preferably one to two times,per day.

When the salt is not applied along with the steroid, it can be appliedfrom 4 to 24 hours, and preferably about 8 hours, before or after theadministration of the steroid. It is preferred that the salt be appliedafter the steroid has been applied.

When the salt-containing formulation is to be used to temporarilythicken the subject's skin, the use of the formulation one to four timesdaily is suggested.

The individual needs of the subject and the desires of the physician maycall for deviations from the routines suggested above.

The term "subject" is intended to mean any mammal upon whose skin orother dermal surface the compositions of the invention can be applied.It is generally preferred that the subject to be treated in accordancewith the invention be a human patient.

Also, the salt-containing formulations of the invention can be employedto ameliorate the dermatological effects of topical steroid use forsubjects of pre-adult age.

DISCUSSION OF DRAWINGS

The drawings show the sequence of epidermal and dermal changes in thesame individual after treatment with nothing (a), 12% ammonium lactate(b), clobetasol propionate (c) and the combination ammonium lactate andclobetasol propionate (d) for four weeks in an open fashion.

a. Control. Normal epidermis (E) showing well developed rete ridges (rr)which results in an undulating dermal/epidermal interface. Horny layer(H) displays typical "basket weave" pattern usually associated withparaffin fixed specimens. Papillary dermis (PD) contains prominentmicrovasculature (mv) as well as a moderate amount of glycosaminoglycans(arrows). Magnification=200×

b. 12% ammonium lactate. Viable epidermis (E) is thicker than controland shows distinct regions of blue coloration (*) indicative of thepresence of glycosaminoglycans. Horny layer (H) maintains the "basketweave" pattern seen in control specimens. Papillary dermis (PD) shows astriking increase in glycosaminoglycan deposition. mv, microvasculature.

c. clobetasol propionate. Viable epidermis (E) is markedly thinner thancontrol, and the horny layer (H) is virtually ablated. Papillary dermis(PD) appears compressed and there is a striking diminution inglycosaminoglycans (arrows) and vascular (mv) profiles.

d. combination treatment with 12% ammonium lactate and clobetasolpropionate. Viable epidermis (E) appears similar in thickness to controlspecimens, and horny layer (H) still retains the "basket weave"appearance. Papillary dermis (PD) shows striking amounds ofglycosaminoglycans (arrows) as well as numerous microvascular (mv)profiles.

In general, viable epidermis (E) is thicker and granular layer (arrows)is more prominent after ammonium lactate treatment. Note preservation of"basket weave" horny layer (H) after ammonium lactate treatment. Noincrease in cellularity is seen in the dermis (D) after ammonium lactatetreatment. *, microvasculature ×150.

EXAMPLES

The following examples serve to illustrate the invention.

EXAMPLE I Effects of Lac-Hydrin® on the Bioavailability of a PotentTopical Corticosteroid Experimental Design

A total of 10 healthy adult volunteers between the ages of 19 and 60years participated in this investigation. There were 5 females and 5males.

After washing the forearms with a bland soap (Ivory®) and patting drywith a soft towel, three circular sites, each measuring 1.2 cm indiameter, were outlined in ink on the volar aspect of the forearm.Twenty microliters of each of the test products (0.05% Temovate®(clobetasol propionate) ointment, Lac-Hydrin® 12% lotion, and thecombination together) were delivered to a designated test site.

On the morning of the first study date, two designated sites on eachforearm received Lac-Hydrin®. The subjects returned 6-8 hours later onthe same day and received Temovate® ointment to a third site and to oneof the sites previously treated with Lac-Hydrin®.

One forearm was then occluded with plastic Saran Wrap® while the siteson the opposite arm were covered with circular plastic chambers in whicha 1 cm hole was punched out from the center. The chambers were appliedover each site and taped at the edges to prevent clothing from rubbingagainst or touching the skin surface. Sixteen (16) hours after the p.m.application the protective chambers and Saran Wrap® were removed andboth forearms were washed again with soap and water and blotted dry witha towel.

Clinical Observations

The degree of blanching at each test site was graded 30 minutes afterthe products were washed from the skin, i.e., 16-17 hours afterapplication, and again 24 hours after the last application of the testproducts.

Grading of the degree of blanching was done in a blind fashion usingstandardized lighting by the investigator who was unaware of the testproduct assignment and who did not participate in the application of thetest products. The following grading scale was used:

0=no vasoconstriction

1=minimal visible blanching

2=definite blanching with well-defined borders

3=more intense blanching

4=intense blanching, spreading beyond the application site.

Results

The individual and total vasoconstriction scores for each test productat both time points (16 and 24 hours) are listed in Tables 1 and 2. Thedegree of blanching for both open and occluded applications ranged from0-3. The mean vasoconstriction scores for both forearms were similar forboth 16 and 24 hour time-points for all test sites. No blanching wasobserved in sites treated with Lac-Hydrin® alone. Prior treatment withLac-Hydrin® did not appear to influence the vasoconstriction byclobetasol propionate ointment in either the open (Table 1) or occluded(Table 2) sites.

The individual scores for both forearms were compared using pairedt-tests and no significant differences were found in the degree ofblanching by prior treatment with Lac-Hydrin®. Thus, the treatment ofthe forearm with Lac-Hydrin® prior to application potent topicalcorticosteroid does not effect the bioavailability of thecorticosteroid.

                  TABLE 1                                                         ______________________________________                                        BLANCHING SCORES FOR OPEN SITES                                                                              Temovate ®                                                  Lac-Hydrin ® 12%                                                                        Ointment                                              Lac-Hydrin ®                                                                        Lotion & Temovate ®                                                                     0.05%                                          Subject  12% Lotion  Ointment 0.05%                                                                              16   24                                    Number                                                                              Arm    16 Hrs. 24 Hrs.                                                                             16 Hrs.                                                                              24 Hrs.                                                                              Hrs. Hrs.                            ______________________________________                                        1     R      0       0     2      2      2    2                               2     L      0       0     1      2      2    2                               3     L      0       0     2      3      2    3                               4     R      0       0     3      1      3    2                               5     R      0       0     2      2      2    2                               6     R      0       0     2      2      2    2                               7     R      0       0     1      1      1    1                               8     L      0       0     1      2      1    2                               9     R      0       0     2      3      2    3                               10    L      0       0     3      2      3    2                               Total        0       0     19     20     20   21                              Score:                                                                        ______________________________________                                    

                  TABLE 2                                                         ______________________________________                                        BLANCHING SCORES FOR OCCLUDED SITES                                                                          Temovate ®                                                  Lac-Hydrin ® 12%                                                                        Ointment                                              Lac-Hydrin ®                                                                        Lotion & Temovate ®                                                                     0.05%                                          Subject  12% Lotion  Ointment 0.05%                                                                              16   24                                    Number                                                                              Arm    16 Hrs. 24 Hrs.                                                                             16 Hrs.                                                                              24 Hrs.                                                                              Hrs. Hrs.                            ______________________________________                                        1     L      0       0     3      3      3    3                               2     R      0       0     3      3      2    3                               3     R      0       0     3      3      3    3                               4     L      0       0     3      1      3    1                               5     L      0       0     3      1      3    3                               6     L      0       0     2      1      2    2                               7     L      0       0     1      1      1    1                               8     R      0       0     1      2      1    2                               9     L      0       0     3      3      3    3                               10    R      0       0     3      3      3    3                               Total        0       0     25     21     24   24                              Score:                                                                        ______________________________________                                    

EXAMPLE II Effects of Lac-Hydrin® on Normal and Corticosteroid-TreatedHuman Skin Experimental Design

Note: In this example "combination" and "salt/steroid combination"refers to the use of the salt at one time and the steroid eight hourslater.

Six healthy young adult males (ages 20-34) served as volunteers. Usingprocedures similar to those of Example I, one site of the ventralforearm received clobetasol-17-propionate cream (0.2 ml; Temovate®,Glaxo) daily for four weeks. Another site on the ventral forearmreceived buffered ammonium lactate (0.2 ml; 12% Lac-Hydrin®, Westwood)daily for four weeks. A third site received a combination of Lac-Hydrin®in the morning (approximately 8:00 am) and Temovate® 8 hours later(approximately 4:00 pm), daily for four weeks. At the end of the fourweek treatment period, one 3 mm punch biopsy was obtained under localanesthesia from each of the treatment sites.

Untreated control biopsies were also secured at the end of four weeks.

Light Microscopy

Each 3-mm punch biopsy was fixed in 10% formalin and processed forconventional paraffin section histology.

Paraffin sections were stained with hematoxylin and eosin and Halescolloidal iron for acid mucopolysaccharides. These sections were usedfor histologic and histogeometric analysis.

Histometric Analysis

For estimation of epidermal thickness, care was taken to cut thesections perpendicularly to the surface. Histometric measurements of theviable epidermal area were made on both hematoxylin eosin and Halesstained sections using computer-assisted image analysis. Measurementswere made from at least four sections per biopsy with each sectionseparated by 50μ.

For estimation of ground substance, histometric measurements were madeon Hales colloidal iron-stained sections using a Vickers M-85microspectrophotometer.

Results

The discussion below is based on the data presented in Table 3.

Corticosteroid

All six subjects showed a marked diminution in the viable epidermis,after 4 weeks of daily treatment with Temovate®. Viable epidermalthickness decreases from an average of 66,803, to 32,476 μ2/mm ofepidermis, representing a 51% decrease in thickness.

Corticosteroid+Lac-Hydrin®

All six subjects showed a diminution in viable epidermis, after 4 weeksof daily treatment with the combination, however, the magnitude wasless.

Viable epidermis decreased from an average of 66,803, to 42,821 μ2/mm ofepidermis, representing a 35% decrease in thickness. When compared withTemovate®, the combination of Lac-Hydrin® and Temovate® resulted in a16% thicker viable epidermis, which was significant at the 0.05 level.

Lac-Hydrin®

Five of the six subjects showed a thickening of the viable epidermis,after 4 weeks of daily treatment with Lac-Hydrin®. One subject (#6)showed virtually no change and another subject (#5) was a weakresponder. Viable epidermal thickness increased from 66,803 to 78,837μ2/mm of epidermis, representing a 20% increase in thickness (Table1,2). When compared with the control, this change was significant at the0.01 level.

These findings indicate that Lac-Hydrin® has a significant sparingeffect on the thinning of the viable epidermis, when used between orafter applications of one of the most, if not the most, potent topicalcorticosteroids, i.e., clobetasol propionate.

In the study, Lac-Hydrin® alone thickened the viable epidermissignificantly. This partially negates the atrophagenic effects of thesteroid.

While not wishing to be bound by any particular theory of operation,applicants note that an increase in Hales stainable material in thedermis suggests that Lac-Hydrin® may stimulate fibroblasts to producemore ground substance (glycosaminoglycans). It is well known thatinhibition of fibroblast synthetic activity, resulting in a decrease inground substance, is one of the major effects of topicalcorticosteroids. Thus, Lac-Hydrin® may also negate the inhibitoryeffects of steroids on the fibroblast.

                  TABLE 3                                                         ______________________________________                                        CHANGE IN THICKNESS OF VIABLE EPIDERMIS TREATMENT                             WITH STEROID, SALT AND SALT/STEROID COMBINATION                               EPIDERMAL THICKNESS*                                                                            % CHANGE                                                                          Salt/             Salt/                                 Subject                                                                             Control Steroid Steroid                                                                             Salt  Steroid                                                                             Steroid                                                                             Salt                            ______________________________________                                        1     58496   25770   35535 80503 -56   -39   38                              2     62506   29345   39532 93657 -53   -37   50                              3     69735   31814   41397 77813 -54   -41   12                              4     73033   46750   57427 82743 -36   -21   13                              5     83400   34477   42700 84834 -58   -48    2                              6     53645   26705   40337 53469 -50   -25    0                              ______________________________________                                         *Values are sq. microns/mm of epidermis                                       **Values represent the delta percent calculations. Negative values            indicate percentage decreases; positive values indicate percentage            increases.                                                               

EXAMPLE III Study of the Effect of Ammonium Lactate on Effectiveness ofSteroid treatment of Rhus Dermatitis (Poison Ivy)

This is a study of topical anti-inflammatory activity conducted in 12healthy volunteer subjects of both sexes. All 12 were enrolled afterthey had developed reactions in four sites to topically applied Rhusextract antigen. The four test sites (2 on each forearm) were treateddaily with measured amounts (˜20 uL) of the following (1) Lac-Hydrin®12% lotion; (2) Temovate® (clobetasol propionate) 0.05% cream; (3) thecombination of Temovate® and Lac-Hydrin®, applied in the a.m. and thep.m., respectively, and (4) Petrolatum U.S.P. (control). After applyingthe treatments to designated sites, the sites were covered withband-aids. Treatments were applied once daily for 5 consecutive days(Monday to Friday) and the sites evaluated visually for edema, erythema,vesiculation etc. on Friday p.m. by a dermatologist.

Efficacy is measured by the degree of resolution of the dermatitiscompared to a treated control site.

Test Materials

The test materials were supplied by the investigator and were labelledalphabetically as A, B or C. The four test sites were assigned eithertreatment A, treatment B, A+B (or B+A) and Treatment C. The treatmentcodes were as follows:

A=Lac-Hydrin® (ammonium lactate) 12% lotion; lot #57B161 (Expiration10/92) Westwood Pharmaceuticals, Inc., Buffalo, N.Y. 14213 (USA) appliedat a.m. visit

B=Temovate® (clobetasol propionate) cream 0.05% lot #Z7740DA (Expiration05/92) Glaxo Dermatology Products, Glaxo, Inc., Research Triangle Park,N.C. 27709 (USA) applied at p.m. visit

A+B=Lac Hydrin® 12% lotion applied at a.m. visit and Temovate® cream0.05% applied at p.m. visit

B+A=Temovate® cream 0.05% applied at a.m. visit and Lac-Hydrin® 12%lotion applied at p.m. visit

C=Vaseline® white petrolatum, USP, lot #938-C Chesebrough-Pond's, Inc.,Greenwich, Conn. 06830 (USA) applied at a.m. visit

Study Group

Rhus-antigen extract (Hollister-Stier Laboratories) was applied asdescribed below to designated sites on both forearms to 19 volunteerswith a strong positive history of poison-ivy dermatitis. Of these, 12developed an acute vesicular dermatitis of equal intensity in all foursites. In the remaining 7, the reactions were either too weak or unequalin intensity and they were dropped from the study. The 12 subjects withequal responses were then allowed to remain in the study and receivedthe treatment schedules as outlined below.

Procedure

After washing the forearms with a bland soap (Ivory) and patting drywith a soft towel, four circular sites were outlined (two on the volaraspect of each forearm) with ink. The dermatitis was induced by theapplication of 10 microliters of 1:50 dilution of poison oak-poison ivyoleoresin (Hollister-Stier Laboratories) to a 0.6cm disc of filterpaper. The filter paper disc was then applied to the skin and taped withimpermeable plastic tape (Blenderm, 3M®). The Blenderm was furthersecured with a non-woven surgical tape (Scanpor). This patch was left inplace for six (6) hours. At the end of six hours, the patch was removedand the area washed with soap and water and then dried.

The induction patches were applied on Friday, Nov. 9, 1990. Thevolunteers returned to the laboratory on Monday, November 12 in themorning, at which time the test sites were examined and graded. Onlyindividuals with equal responses (dermatitis) in all four sites wereallowed to continue in the study.

Treatment Plan

Each site received about 20 uL of A, B, A+B or C as described under"materials". Test product applications were randomized according to arandomization schedule prepared by the investigator (Appendix B). Thetest products were gently rubbed into the sites using clean glass rodsand the sites were then covered by a band-aid to prevent rubbing againstclothing, etc. In six volunteers (#1, #2, #3, #4, #5 and #11),Lac-Hydrin® was applied first (in the a.m.) followed by Temovate® in thep.m., while in the remaining six volunteers, (#6, #7, #8, #9, #10 and#12) the sequence of applications were reversed viz. Temovate® wasapplied in the a.m. and Lac-Hydrin® in the p.m. The remaining three testsites received either Lac-Hydrin® alone (A) in the a.m., Temovate® alonein the p.m. or Vaseline in the a.m.

Treatments were continued for 5 consecutive days. On the last day, thesites were visually graded by the investigator who was unaware ofproduct assignment and who did not participate in product application ortreatment. The forearms were also photographed after they were graded.

Grading Scale

The following scale was used to grade all Rhus-induced dermatitis:

0=complete clearing

1=minimally elevated or palpable border with faint erythema

2=more elevated lesion with diffuse edema or palpable infiltration andmoderate erythema

3=uniformly raised lesions with intense edema, erythema and scaling orcrusting

4=marked edema, intense erythema and vesiculation

Adverse Reactions

Patients were instructed by the investigator to report immediately theoccurrence of any adverse experience. The adverse reaction(s), if any,were recorded and described in detail (nature and intensity). Dates ofoccurrence of any such reaction were noted, along with dates of thedetails concerning any necessary discontinuation or interruption oftherapy. Any adverse reaction would have been reported immediately tothe sponsor by telephone and in writing within five days.

Results

Of the 19 original volunteers, only the 12 volunteers listed in Table 1qualified for continuation in the study and completed the investigationas outlined. There were no adverse reactions or unexpected side-effectsof any kind.

The reaction scores recorded at the outset of the study beforetreatments were started are listed in Table 4. The mean score (±S.D.)for each test site was 3.4+0.5. The scores recorded on the last day oftreatment are displayed in Table 5.

                  TABLE 4                                                         ______________________________________                                        GRADES - DAY 0, by Treatment                                                          Lac-                         Vaseline ®                                   Hydrin ®                 White                                    Subject 12%      Temovate ®                                                                           Lac-hydrin &                                                                           Petrolatum                               Number  Lotion   Cream 0.05%                                                                              Temovate (U.S.P.)                                 ______________________________________                                        01      4        4          4        4                                        02      3        3          3        3                                        03      4        4          4        4                                        04      3        3          3        3                                        05      3        3          3        3                                        06      4        4          4        4                                        07      4        4          4        4                                        08      3        3          3        3                                        09      3        3          3        3                                        10      3        3          3        3                                        11      4        4          4        4                                        12      3        3          3        3                                        Mean (X) ±                                                                         3.4      3.4        3.4      3.4                                      S.D.    0.5      0.5        0.5      0.5                                      ______________________________________                                    

                  TABLE 5                                                         ______________________________________                                        GRADES - DAY 4, by Treatment                                                          Lac-                         Vaseline ®                                   Hydrin ®        Lac-     White                                    Subject 12%      Temovate ®                                                                           hydrin ® &                                                                         Petrolatum                               Number  Lotion   Cream 0.5% Temovate ®                                                                         (U.S.P.)                                 ______________________________________                                        01      4        2          2        4                                        02      3        1          1        3                                        03      4        2          1        4                                        04      3        1          1        3                                        05      1        1          1        2                                        06      2        0          0        2                                        07      4        3          2        4                                        08      3        1          1        3                                        09      2        0          0        2                                        10      3        2          2        3                                        11      4        1          1        4                                        12      1        1          2        1                                        Mean (X) ±                                                                         2.8      1.3        1.2      2.9                                      S.D.    1.1      0.9        0.7      1.0                                      ______________________________________                                    

There was no major difference in the mean reaction score followingtreatment by Lac-Hydrin® compared to petrolatum U.S.P. (mean scores of2.8 and 2.9 respectively). Nor were there any discernable differencesbetween sites treated with Temovate® and with Temovate® plusLac-Hydrin®, regardless of the sequence or order of application.

The results confirmed that Lac-Hydrin® had no noticeable effect abovethat of Petrolatum and did not influence the anti-inflammatory activityof Temovate®.

Temovate® alone or with Lac-Hydrin® produced a highly significant(P=0.0001) effect in terms of enhancing the resolution of the dermatitiscompared to treatment with petrolatum alone or Lac-Hydrin® alone.

DISCUSSION

There is little doubt that the use of Lac-Hydrin® after the use ofcorticosteroids results in a sparing of the viable epidermis. Examples Iand III indicates that this sparing effect was not due to eitherdilution of the steroid or diminution of its efficacy.

The data generated for Lac-Hydrin® on normal skin (Example II) suggeststhat this product may behave like a retinoid with respect to changes inthe morphology of the epidermis and dermis (thickens the epidermis,increases ground substance). While the Lac-Hydrin® effects do not appearto be as profound as those of the retinoids, significant changes areachieved without any clinical signs of irritation. This is a majoradvantage over retinoid therapy for such conditions as aging skin.

It is contemplated, then, that long-term use of topical Lac-Hydrin®could reverse some of the changes that normally occur to aged skin(thinning of the epidermis and dermis), with much less irritation thanis generally caused by retinoids.

Reasonable variations, such as those which would occur to a skilledartisan, can be made herein without departing from the scope of theinvention.

What is claimed is:
 1. A method for decreasing the reduction of thethickness of viable epidermis of mammalian skin contacted with a steroidin an amount that causes said reduction comprising contacting said skinwith a viable epidermis thickness increasing amount of adermatologically acceptable salt of an alpha-hydroxy acid of theformula: ##STR2## wherein R is hydrogen or a C₁₋₅ hydrocarbon group,said decrease in the reduction of the thickness of the viable epidermisbeing in comparison to skin contacted with said amount of said steroidbut not contacted with said dermatologically acceptable salt of analpha-hydroxy acid.
 2. The method of claim 1, wherein the salt is areaction product of said alpha-hydroxy acid and a metal ion containingbase or a base containing a nitrogen atom present in an ammonium ion oran amine.
 3. The method of claim 1, wherein the steroid is in adermatologically acceptable composition containing from about 0.005 wt %to about 3 wt % steroid.
 4. The method of claim 1, wherein said skin iscontacted with the steroid and the α-hydroxy acid salt simultaneously.5. The method of claim 2, wherein said skin is contacted with thesteroid and the α-hydroxy acid salt simultaneously.
 6. The method ofclaim 3, wherein said skin is contacted with the steroid and theα-hydroxy acid salt simultaneously.
 7. The method of claim 1, whereinsaid skin is contacted with the steroid and the α-hydroxy acid saltsequentially.
 8. The method of claim 2, wherein said skin is contactedwith the steroid and the α-hydroxy acid salt sequentially.
 9. The methodof claim 3, wherein said skin is contacted with the steroid and theα-hydroxy acid salt sequentially.
 10. The method of claim 5, whereinsaid skin is contacted with the α-hydroxy acid salt at a time period upto eight hours after said contacting with steroid.
 11. A method fordecreasing skin atrophy of mammalian skin contacted with a steroid in anamount that causes skin atrophy comprising contacting said skin with askin atrophy decreasing amount of a dermatologically acceptable salt ofan alpha-hydroxy acid of the formula: ##STR3## wherein R is hydrogen ora C₁₋₅ hydrocarbon group, said decrease in the reduction of skin atrophybeing in comparison to skin contacted with said amount of said steroidbut not contacted with said dermatologically acceptable salt of analpha-hydroxy acid.
 12. The method of claim 11, wherein the salt is areaction product of said alpha-hydroxy acid and a metal ion containingbase or a base containing a nitrogen atom present in an ammonium ion oran amine.
 13. The method of claim 11, wherein the steroid is in adermatologically acceptable composition containing from about 0.005 wt %to about 3 wt % steroid.
 14. The method of claim 11, wherein the steroidand the α-hydroxy acid salt are applied simultaneously.
 15. The methodof claim 12, wherein the steroid and the α-hydroxy acid salt are appliedsimultaneously.
 16. The method of claim 12, wherein the steroid and theα-hydroxy acid salt are applied simultaneously.
 17. The method of claim11, wherein the steroid and the α-hydroxy acid salt are appliedsequentially.
 18. The method of claim 12, wherein the steroid and theα-hydroxy acid salt are applied sequentially.
 19. The method of claim13, wherein the steroid and the α-hydroxy acid salt are appliedsequentially.
 20. The method of claim 11, wherein the α-hydroxy acidsalt is applied to the skin at a time period up to eight hours aftersaid contacting with steroid.